The objectives of this project are to study the immunologic and immunopathologic processes during the course of viral infections. Emphasis is presently being placed on the role of viruses in immediate hypersensitivity responses. The release of histamine from leukocytes (basophils) of allergic individuals following stimulation with ragweed antigen (antigen E) or anti-IgE is a reliable in vitro model for immediate hypersensitivity reactions (allergic reaction). Using this in vitro model, we have shown that several common viruses can enhance the release of histamine from leukocytes stimulated with antigen E. Further experiments showed that this enhancement was due to a soluble substance which appears to be interferon. Studies now are in progress to: 1) further characterize the soluble factor as interferon and to determine if RNA or protein synthesis are required for the enhancement, 2) establish an in vivo model of viral- or interferon-induced enhancement of immediate hypersensitivity reactions, and 3) study the effect of interferon on basophil chemotaxis. BIBLIOGRAPHIC REFERENCES: Ida, S., Hooks, J.J., Siraganian, R.P., and Notkins, A.L.: Enhancement of IgE-mediated Histamine Release by Viruses: Role of Interferon. J. Exp. Med. 145:892-906, 1977. Rytel, M.W., and Hooks, J.J.: Induction of Immune Interferon by Murine Cytomegalovirus. Proc. Soc. Exp. Biol. & Med. (in press) 1977.